Also consider refurbished machines (eg via the bay) - I have in the past got x230 thinkpads w/ 16GB RAM and i5 (or better) processors for under 200 quid.... That was 3-4 years ago (at least) and they're still going strong! Extra money could be used to buy an external monitor so you have a big screen, plus keyboard/mouse (obvs much cheaper) - and then you have a good home set-up that is also very portable.
NB, other thought is to stick linux on it - very powerful, does all that you require; I used darktable for photo processing and it's very powerful with lots and lots of features.
Also consider refurbished machines (eg via the bay) - I have in the past got x230 thinkpads w/ 16GB RAM and i5 (or better) processors for under 200 quid.... That was 3-4 years ago (at least) and they're still going strong! Extra money could be used to buy an external monitor so you have a big screen, plus keyboard/mouse (obvs much cheaper) - and then you have a good home set-up that is also very portable.
NB, other thought is to stick linux on it - very powerful, does all that you require; I used darktable for photo processing and it's very powerful with lots and lots of features.